M8950 Charging system

[tylergrant20112011]

I have a m8950 and recently the charging system on my tractor is not working. It is running off battery power alone. I've replaced the alternator and still only getting 12v at the battery when running. Is there a inline fuse or perhaps an external regulator on this tractor? Also if someone can give me information on buying a repair manual that would be great.

Thanks

 

[North Idaho Wolfman]

Have you checked power into the alternator?

You will have to get the WSM from either eBay, or a Kubota dealer.

 

[tylergrant20112011]

I've checked the power at the battery while running and it was reading 12.4. Also checked the power on the post of the alternator it was reading 12.4 also. The red wire and the 3 wire plug from the alternator goes to the cab.

 

[tylergrant20112011]

Which wire is the power wire coming from the ignition switch feeding 12v to the alternator?

 

[Dave_eng]

From looking at the wiring upgrade for a B7100 which is of the same era as your tractor I believe you have a voltage regulator.

The three terminals on your alternator with letters E, F & N correspond to three terminals that would be on the regulator.

Do you see anything that looks like this regulator on your tractor? The 3 wire connector would have some connection to it if it exists.

For $14 I would be inclined to buy a new regulator since you already bought a new alternator.

Dave

 

[tylergrant20112011]

Which wire is the power wire coming from the ignition switch feeding 12v to the alternator?

 

[Dave_eng]

Which wire is the power wire coming from the ignition switch feeding 12v to the alternator?

Please read my post #5.

The 12 volt signal to start producing power goes to the voltage regulator not the alternator.

Dave

 

[tylergrant20112011]

Please read my post #5.

The 12 volt signal to start producing power goes to the voltage regulator not the alternator.

Dave

After removing the side wall from the dash, I found the problem. The regulator was unplugged. I'm guessing it somehow got stuck to the clutch linkage and whenever the clutch was pressed, it unplugged it. Thanks for the help. There is still one problem though, the battery light is still on, on the instrument panel.

 

[Dave_eng]

After removing the side wall from the dash, I found the problem. The regulator was unplugged. I'm guessing it somehow got stuck to the clutch linkage and whenever the clutch was pressed, it unplugged it. Thanks for the help. There is still one problem though, the battery light is still on, on the instrument panel.

What is the battery voltage now with the engine running?
Have you checked all fuses?

Dave

 

[GeoHorn]

My “M” has it’s regulator inside the alternator.
Several things come to mind: New alternators can be bad. Old alternators can be good.
Did you ever take your alternators to an alternator shop and have them tested?
It’ll do you no good to keep changing parts if they’re both bad, and it’ll do no good to keep buying new replacements for good parts.
A bad terminal, or bad ground can hide all sorts of troubles, so just switching out parts is not a good way to fix things.

 

[Dave_eng]

My “M” has it’s regulator inside the alternator.
Several things come to mind: New alternators can be bad. Old alternators can be good.
Did you ever take your alternators to an alternator shop and have them tested?
It’ll do you no good to keep changing parts if they’re both bad, and it’ll do no good to keep buying new replacements for good parts.
A bad terminal, or bad ground can hide all sorts of troubles, so just switching out parts is not a good way to fix things.

His regulator is external..... hence the three small terminals

Dave

 

[tylergrant20112011]

What is the battery voltage now with the engine running?
Have you checked all fuses?

Dave

Battery voltage with the engine running is 14.3. I checked the fuses before I found the regulator wire unplugged but will check again to make sure.

 

[eserv]

After removing the side wall from the dash, I found the problem. The regulator was unplugged. I'm guessing it somehow got stuck to the clutch linkage and whenever the clutch was pressed, it unplugged it. Thanks for the help. There is still one problem though, the battery light is still on, on the instrument panel.

The M8950 battery light indicates the electrolyte level in the battery. It usually doesn't work with anything but the original battery because the sensor can't be installed in the replacement battery. The ammeter is the indication if it is charging or not.